Harnessing the power of Nutrigenomics to optimise your health

Switched On, By Dr Christine Houghton

The below is an Excerpt from ‘Switched On’, 2016 Chapter 9


One of the most extraordinary findings of our times is a small sulphur-containing molecule, Sulforaphane, derived mainly from consuming Cruciferous vegetables such as Broccoli. Although the plant doesn’t actually contain any sulforaphane itself, it does contain two essential compounds (one of which is an enzyme) needed to produce sulforaphane under the right conditions.

What makes Sulforaphane so extraordinary is its ability to activate the cellular ‘switch’ Nrf2, which controlls the 200 or so genes (28) related to the cell’s defence system. In fact, Sulforaphane is considered to be the most powerful of the naturally-occuring substances capable of doing this (29). Better still, its high bioavailability (30) of around 80% makes it a very practical supplement to the well-balanced daily diet. As we have seen, much of the cell’s ability to defend itself is due to its ability to activate three key processes as shown.

With these protective genes able to ‘switch on’, the cells operate more efficiently, energy is produced more readily, immune and inflammatory (31) pathways are well-regulated and the cell’s ‘spring cleaning’ processes remove waste materials before they have a chance to damage delicate cellular structures, including DNA. When all 50 trillion of your cells are working just as Nature intended, your body can operate at its peak. As we said at the outset, when your cells are healthy, YOU are healthy!

Status of Current Sulforaphane Research

Much of the research conducted on Sulforaphane in the last decade has focused on its potential to prevent diseases for which mainstream medicine has few solutions; cancer (32), heart disease (33), degenerative brain disorders (34) and gastric ulcers (35) as the most notable. Not all this research has yet undergone clinical trials in humans but the number of research groups around the world investigating different aspects of this remarkable nutrigenomic compound, continues to grow.

This more recent research has also helped to explain why cruciferous vegetables (36), more than other vegetable families, have been associated with prevention against disease in general, but especially against cancer.

Diabetes and Sulforaphane

My own clinical research in Brisbane, Australia is focused on the possible role of Sulforaphane in preventing the life-threatening complications of Type 2 diabetes. There is already substantial evidence that the primary upstream event which leads to all other complications of diabetes is oxidative stress (37). It appears that the process is initiated by the Superoxide free radical and as we will see in the nest chapter, a melon-derived nutrigenomic compound is capable of switching on the genes which code for the three Antioxidant Enzymes, led by Superoxide dismutase (SOD).

Where is Sulforaphane found?

It has long been known that broccoli doesn’t actually contain any Sulforaphane at all. Instead, the plant contains an active precursor compound known as Glucoraphanin in a sac within the plant cell and an enzyme, myrosinase in a separate sac. Cutting or chewing the plant breaks the small sacs and a chemical reaction follows which stimulates the myrosinase enzyme to convert the precursor compound, Glucoraphanin to Sulforaphane.

Cooking destroys the activity

Sulforaphane is not very stable once it is formed, so it needs to be consumed fairly soon. The other issue to consider is that because the enzyme myrosinase is heat-sensitive, cooking destroys it.

Consuming cooked broccoli vegetable provides the precursor but without the active myrosinase enzyme present as well, little or no Sulforaphane can be produced. Raw broccoli is not commonly consumed, so few of us really obtain maximal benefit from eating it. There is some research to show that the intestinal bacteria which are a normal part of the human intestine are capable of converting glucoraphanin to active sulforaphane, however, it turns out that these bacterial microflora are likely to convert as little as zero to 8% of the glucoraphanin (38).

Vegetable versus sprout

A research group in the U.S. in the 1900s discovered that the precursor substance, Glucoraphanin is found most abundantly in the tiny sprouted seed of the broccoli plant; in fact the sprouted seed contains 20-50 times more of this compound than the mature vegetable. This finding makes it possible to obtain significant amounts of bioactive sulforaphane from only small quantities of plant material.

As the science on this remarkable compound continues to unfold, it has become imperative that it be conveniently available as a functional food or nutraceutical supplement.

It is possible for you to grow your own sprouts from broccoli seeds but such a process requires the time and a level of dedication few could muster. Oddly enough, the fresh sprouts contain an inhibitor (39) which partially hijacks the conversion from glucoraphanin to sulforaphane, producing an inactive sulforaphane nitrile.

Broccoli Sprout Powder for convenience

The logical option is to produce powdered broccoli sprout. However, this is not as easy in practice as it might seem because it is necessary to carefully dry the delicate sprouts while still retaining the myrosinase enzyme activity.

Although industry is very experienced at producing many dried vegetable powders using the usual drying techniques, specialised technology is required to produce a broccoli sprout powder which can be standardised for an optimal Sulforaphane yield. CAUTION: Be very cautious about products which are brown and are simply made from unsprouted seeds; broccoli seeds contain toxic, erucic acid which is toxic to the heart but fortunately disappears during sprouting.

Sulforaphane Yield versus Sulforaphane Potential

Because the specialised technique required to produce a broccoli sprout powder with a consistently high Sulforaphane Yield is not widely-known, some of the products which have appeared on the market are of poor quality. When tested in the lab, many have been shown to have little or no myrosinase enzyme activity. However, the label can be confusing because these products may claim a high Glucoraphanin level. Others may also claim a numerical value for their ‘Sulforaphane Potential’. The ‘Potential’ as it turns out, is simply a calculated value based on a theoretical 100% conversion to sulforaphane if the product contained the enzyme.

Some products blatantly (or in ignorance) claim that their powder contains a defined amount of sulforaphane. As is already clear, the product CANNOT contain sulforaphane itself. The ideal product contains a high level of glucoraphanin along with active enzymes which should have been retained through careful processing. Once the powder is consumed, moisture activates the process of converting the glucoraphanin to bioactive sulforaphane.

You can see how confusing it can be for the consumer to evaluate the worth of a particular product. However, once you do find a product which satisfies the criteria for bioactivity, it’s surely worth making it an integral part of your day-to-day routine.

Healthier Aging

I’ve never been comfortable with the term, ‘Anti-Aging‘ because surely there is no such thing! However, I do like the concept of healthier aging because it is something over which we do have some control. Unfortunately, as we age, the cellular defence mechanisms become less efficient, making us more prone to illness. Even the Master Switch Nrf2 gets a bit ‘rusty’ and doesn’t respond to the signals as efficiently as it did when we were younger (40).

Immune Responses

A fascinating 2008 study (41) on aged animals showed that Sulforaphane restored Nrf2 function to the levels of much younger animals. Abnormalities in the immune system commonly accompany old age and this study showed that using Sulforaphane increased Glutathione levels in these animals. Moreover, their immune function returned to normal and signs of skin allergy normalised. This has rather exciting possibilities for future research but whether the same response will occur in humans is yet to be seen.

This has been an excerpt from ‘Switched On’ Harnessing the Power of Nutrigenomics to Optimise Your health, by Dr Christine Houghton, PhD, B.Sc.(Biochem.), R.Nutr. Nutritional Biochemist

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